Clamp device

ABSTRACT

To provide a clamp device capable of simply clamping an object to and removing it from a support base. In the clamp device, a body, a pressing member for pressing a workpiece, and a rotary member are allowed to rotate relative to each other. The pressing member rotates between a first rotary position not facing the workpiece and a second rotary position facing the workpiece. In the second rotary position, the pressing member is also movable between a press releasing position and a pressing position. Here, when the rotary member is rotated from one rotary position to a middle rotary position, the pressing member, while being held in the press releasing position by a holding means, is rotated by a contact means from the first rotary position to the second rotary position as the rotary member rotates. Next, when the rotary member is rotated to another rotary position, the pressing member, while remaining in the second rotary position by the rotary range restricting means, is moved to the pressing position by an interlock means.

BACKGROUND OF THE INVENTION

The present invention relates to a clamp device for clamping an object, such as a workpiece, to a fixture base, a machine table or the like.

Conventionally, there has been a clamp device 511, as shown in FIG. 17, for clamping an object, such as a workpiece, to a fixture base, an MC pallet, a machine table or the like. The clamp device 511 includes: a body 512 that is attached to a support base 501; a pressing member 513 for clamping the workpiece 502; a tightening bolt 514; and a coil spring 515. The body 512 has a shank portion 512 a that is formed with a thread hole 512 b. In addition, the pressing member 513 is attached to the shank portion 512 a so as to rotate and slide axially. The pressing member 513 is formed with a claw portion 513 a projecting sideways to press the workpiece 502. The tightening bolt 514 passes through the pressing member 513 and engages the thread hole 512 b formed in the body 512. As the tightening bolt 514 is tightened into the thread hole 512 b, the pressing member 513 slides axially, causing the claw portion 513 a to press the workpiece 502. Thus the workpiece 502 is fixed to the support base 501.

In the conventional clamp device 511 as described above, the workpiece 502 is clamped as follows: first, in the state in which the claw portion 513 a of the pressing member 513 is rotated to a position not facing the workpiece 502, the workpiece 502 is placed on the support base 501; then the pressing member 513 is rotated so that the claw portion 513 a faces the workpiece 502. After that, the tightening bolt 514 is tightened until the workpiece 502 is clamped to the support base 501. If the workpiece 502 is to be removed, first the tightening bolt 514 is loosened. After that, the pressing member 513 is rotated until the claw portion 513 a of the pressing member 513 does not face the workpiece 502. Then the workpiece 502 can be removed from the support base 501. In this way, the conventional clamp device 511, if the workpiece 502 is clamped to or removed from the support base 501, requires two different kinds of work, that is, one work of rotating the pressing member 513 and the other work of tightening up or loosening the tightening bolt 514, which is very cumbersome.

The present invention has been made to overcome the conventional drawbacks described above. The object of the invention is to provide a clamp device that enables easier attachment and removal of an object to be clamped to and from a support base.

BRIEF SUMMARY OF THE INVENTION

To achieve the above object a clamp device according to the present invention is constituted as follows.

That is to say, the clamp device according to the invention is a clamp device which clamps an object to a support base and comprises: a body detachably secured to the support base, a pressing member for clamping the object, and a rotary member. Here, the body, the pressing member, and the rotary member are combined so as to rotate relative to each other about an axis. The pressing member rotates between a first rotary position not axially facing the object and a second rotary position axially facing the object. The rotary member rotates between one rotary position on the first rotary position side and another rotary position past a middle rotary position on the second rotary position side. The pressing member axially translates between a press releasing position on a press releasing side and a pressing position on a pressing side so as to press the object and release the press in the second rotary position. Here, the clamp device has: a contact means, a holding means, a rotary range restricting means, and an interlock means. The contact means forces the pressing member and the rotary member to contact with each other so that the pressing member rotates between the first rotary position and the second rotary position as the rotary member rotates. The holding means holds the pressing member in the press releasing position between the first rotary position and the second rotary position. The rotary range restricting means prevents the pressing member from rotating from the second rotary position to a side opposite the first rotary position. The interlock means moves the pressing member in the second rotary position, between the press releasing position and the pressing position, and interlocks with the rotation of the rotary member between the middle rotary position and the other rotary position.

When the rotary member is rotated from the one rotary position to the middle rotary position, the pressing member, while being held in the press releasing position by the holding means, is rotated by the contact means from the first rotary position to the second rotary position as the rotary member rotates. When the rotary member is rotated from the middle rotary position to the other rotary position, the pressing member, while remaining in the second rotary position by the rotary range restricting means, is moved by the interlock means from the press releasing position to the pressing position and presses the object. When the rotary member is rotated from the other rotary position to the one rotary position side, the pressing member is moved by the interlock means from the pressing position to the press releasing position side, and is rotated by the contact means from the second rotary position to the first rotary position as the rotary member rotates.

In this way, if the object is to be clamped to the support base using the clamp device, the object is placed in the clamping position followed by rotating the rotary member from the one rotary position to the other rotary position past the middle rotary position. In such a way, the pressing member is rotated from the first rotary position not facing the object to the second rotary position facing the object, as the rotary member rotates up to the middle rotary position. By rotating the rotary member to the other rotary position, the pressing member, while remaining in the second rotary position, moves from the press releasing position to the pressing position, to press the object. In this way, the object is clamped to the support base.

In contrast, if the object is to be removed from the support base, the rotary member is rotated from the other rotary position to the one rotary position. This causes the pressing member to move from the pressing position to the press releasing position side, and rotates from the second rotary position facing the object to the first rotary position not facing the object, resulting in the removal of the object from the support base. In other words, by use of this clamp device, when the object to be clamped is placed on and clamped to the support base or the object is removed from the support base, the pressing member is rotated between the first rotary position not facing the object and the second rotary position facing the object by rotating the rotary member. Then the pressing member is moved between the press releasing position and the pressing position. It is therefore easy to clamp the object to the support base and remove it therefrom.

In the clamp device according to the invention, the body of the clamp device is provided with an axial bore, the rotary member has a shank portion that is rotatably inserted in the axial bore, and the rotary member rotates relative to the body about the axis. The pressing member has a through-hole for the shank portion to pass and is allowed to rotate about the axis relative to the rotary member. In other words, in the clamp device, the shank portion of the rotary member passes through the axial bore formed in the body and also through the through-hole formed in the pressing member, so that the body, the pressing member, and the rotary member are allowed to rotate relative to each other about the axis.

Also, the rotary range restricting means includes: a projection disposed in one of the body and the pressing member; and a recess such as a hole or a cut out formed in the other of the body and the pressing member, to receive the projection and allow the projection to move. Here, when the pressing member rotates from the first rotary position to the second rotary position, the projection moves relative to and within the recess and comes into contact with the inside surface thereof, resulting in prevention of further movement of the projection.

The holding means includes a resilient body for urging the pressing member toward the press releasing position from the pressing position. In this way, the pressing member is urged by the resilient body toward the press releasing position and held in the press releasing position between the first rotary position and the second rotary position.

The interlock means comprises: a guide means for axially guiding the rotary member as it rotates, and a support means for supporting the pressing member so that it moves between the press releasing position and the pressing position as the rotary member axially translates. Owing to the rotation of the rotary member between the middle rotary position and the other rotary position, the rotary member is guided to axially translate. Along with this movement, the pressing member supported by the support means moves between the press releasing position and the pressing position.

The guide means includes: a guided projection disposed in one of the body and the rotary member; and a guide surface provided in the other of the body and the rotary member, for guiding the guided projection relative to the guide surface. In this way, as the guided projection is guided relative to and with the guide surface, the rotary member is guided to axially translate.

The support means includes: a resilient element for urging the pressing member toward the press releasing position from the pressing position, and a receiving portion disposed in the rotary member for receiving the pressing member against the urging force of the resilient element. Therefore, when the rotary member rotates between the middle rotary position and the other rotary position and is guided by the guide means to axially translate, along with this movement, the pressing member urged by the resilient element, is received on the receiving portion of the rotary member and is translated between the press releasing position and the pressing position.

The contact means includes a resilient member for urging a first sliding surface and a second sliding surface of the pressing member and the rotary member facing each other to come into tight contact with each other. In this way, as the first sliding surface and the second sliding surface of the pressing member and the rotary member facing each other are urged by the resilient member to come into tight contact with each other, the pressing member securely rotates between the first rotary position and the second rotary position as the rotary member rotates.

The contact means comprises: the resilient member, an engagement recess provided on one of the pressing member and the rotary member; and an engagement member that is provided in the other of the pressing member and the rotary member and has an engagement portion resiliently urged to releasably engage the engagement recess. Engagement of the resiliently urged engagement portion with the engagement recess as described above makes it possible to stop relative rotation of the pressing member and the rotary member, so that the pressing member rotates more securely between the first rotary position and the second rotary position as the rotary member rotates.

The pressing member is guided, while being located in the press releasing position, to move from a side distant from the pressing position to a side near the pressing position as the pressing member rotates from the first rotary position to the second rotary position. In this way, with the press releasing position having a range, when the pressing member rotates from the first rotary position to the second rotary position, the pressing member moves from the side distant from the pressing position to the side near the pressing position.

Therefore, even if any obstacle is present on the way the pressing member moves from the first rotary position to the second rotary position, the pressing member can pass the obstacle. Moreover, because the pressing member approaches the pressing position while it rotates from the first rotary position to the second rotary position, it is possible to reduce the stroke defined between the press releasing position and the pressing position in the second rotary position. Therefore, it is possible to increase the force of the pressing member for pressing the object.

BRIEF DESCRIPTION OF DRAWINGS

Accompanying the specification are figures which assist in illustrating the embodiments of the invention, in which:

FIG. 1 is an exploded, perspective view of a clamp device of an embodiment according to the invention;

FIG. 2 is a plan view, in which a rotary member is in one rotary position, and a pressing member is in a first rotary position and in a press releasing position;

FIG. 3 is a cross sectional view, taken along a line A-A, in FIG. 2;

FIG. 4 is a plan view, in which the rotary member is in a middle rotary position, and the pressing member is in a second rotary position and in the press releasing position;

FIG. 5 is a cross sectional view, taken along a line B-B, in FIG. 4;

FIG. 6 is a plan view, in which the rotary member is in another rotary position, and the pressing member is in the second rotary position and in the pressing position;

FIG. 7 is a cross sectional view, taken along a line C-C, in FIG. 6;

FIG. 8 is a plan view, in which the rotary member is in the other rotary position and in the maximum rotary position, and the pressing member is in the second rotary position and in the maximum pressing position;

FIG. 9 is a cross sectional view, taken along a line D-D, in FIG. 8;

FIG. 10 is a perspective view, showing a state in use with a workpiece yet to be attached or removed;

FIG. 11 is a perspective view, showing a state in use with a workpiece attached;

FIG. 12 is a cross sectional view, showing a first modification of the embodiment of the clamp device according to the invention;

FIG. 13 is a perspective view, showing a second modification of the embodiment of the clamp device according to the invention;

FIG. 14 is a plan view, showing a third modification of the embodiment of the clamp device according to the invention;

FIG. 15 is a cross sectional view, taken along a line E-E, in FIG. 14;

FIG. 16 is a cross sectional view, showing a fourth modification of the embodiment of the clamp device according to the invention; and

FIG. 17 is a cross sectional view, showing a conventional clamp device.

DETAILED DESCRIPTION OF THE INVENTION

Clamp devices embodied according to the invention are described below, with reference to the accompanying drawings.

FIGS. 1 to 11 show a clamp device as an embodiment of the invention. Referring to FIG. 3, reference numeral 1 denotes a support base, such as a fixture base, that is attached to a machine table or a pallet of a machine tool such as a machining center. Reference numeral 2 represents for example a workpiece, an object to be clamped, as an object to be processed. Reference numeral 3 represents a clamp device for clamping the workpiece 2 to the support base 1.

The clamp device 3 includes: a body 4 removably attached to the support base 1; a pressing member 5 for clamping the workpiece 2; and a rotary member 6. The body 4, the pressing member 5, and the rotary member 6 are combined so as to rotate relative to each other about an axis 7. Thus, the pressing member 5 is allowed to rotate between a first rotary position (See FIGS. 2 and 3) not axially facing the workpiece 2 and a second rotary position (See FIGS. 4 and 5) axially facing the workpiece 2. The rotary member 6 is allowed to rotate between one rotary position (See FIG. 2) on the first rotary position side and another rotary position (See FIGS. 6 and 8) past a middle rotary position (See FIG. 4) on the second rotary position side. The body 4 has an axial bore 4 a therethrough. On the other hand, the rotary member 6 has a shank portion 6 a that is rotatably inserted in the axial bore 4 a of the body 4, so that the rotary member 6 may axially rotate relative to the body 4. The pressing member 5 has a through-hole 5 a to permit the shank portion 6 a of the rotary member 6 to pass, so that the pressing member 5 may axially rotate relative to the rotary member 6. Thus, as for this clamp device 3, the body 4, the pressing member 5, and the rotary member 6 are allowed relative axial rotation because the shank portion 6 a of the rotary member 6 is inserted in the axial bore 4 a of the body 4 and the through-hole 5 a of the pressing member 5.

The pressing member 5 axially translates between a press releasing position (See FIG. 5) on a press releasing side and a pressing position (See FIGS. 7 and 9) on a pressing side so that it presses the workpiece 2 and releases the press in the second rotary position.

Here, the clamp device 3 includes a contact means 110, a holding means 120, a rotary range restricting means 130, and an interlock means 140.

The contact means 110 causes the pressing member 5 and the rotary member 6 to contact each other so that the pressing member 5 rotates between the first rotary position (See FIGS. 2 and 3) and the second rotary position (See FIGS. 4 and 5) as the rotary member 6 rotates. Specifically, the contact means 110 includes a coil spring 8 as a resilient member for urging a first sliding surface 5 b and a second sliding surface 6 b of the pressing member 5 and the rotary member 6 facing each other to contact closely each other. More specifically, the contact means 110 has: the coil spring 8 serving as a resilient member, an engagement recess 111 disposed in one of the pressing member 5 and the rotary member 6; and an engagement member 113 which is disposed in the other of the pressing member 5 and the rotary member 6 and has an engagement portion 112 resiliently urged to releasably engage the engagement recess 111. The engagement recess 111 is formed in the pressing member 5, while the engagement member 113 is formed in the rotary member 6. The engagement member 113 is a plunger 9 that is attached to, and embedded in, the rotary member 6. The engagement portion 112 is a pressing piece 9 a such as a ball, which is placed at the tip of the plunger 9. The pressing piece 9 a is resiliently urged by a spring 9 b disposed in the plunger 9.

The holding means 120 holds the pressing member 5 in the press releasing position between the first rotary position (See FIGS. 2 and 3) and the second rotary position (See FIGS. 4 and 5). Specifically, the holding means 120 includes the coil spring 8 as a resilient body for urging the pressing member 5 toward the press releasing position from the pressing position. Thus, the pressing member 5 is urged by the coil spring 8 as a resilient body toward the press releasing position on the press releasing side from the pressing position on the pressing side and held in the press releasing position between the first rotary position and the second rotary position. More specifically, the coil spring 8 is interposed between the body 4 and the pressing member 5 so as to urge the pressing member 5. The coil spring 8 urges the pressing member 5 not directly but indirectly through an outer cylinder 10 which will be described later. As described above, while the pressing member 5 is urged by the coil spring 8, the urging force is received by a receiving portion 6 c of the rotary member 6, to be described later, and the pressing member 5 is held in the press releasing position.

The rotary range restricting means 130 prevents the pressing member 5 from rotating from the second rotary position to the side opposite the first rotary position. Specifically, the rotary range restricting means 130 includes a projection 131 disposed in one of the body 4 and the pressing member 5, and a recess 132 such as a hole or a cut out, which is provided in the other of the body 4 and the pressing member 5 and receives the projection 131 for movement therein. As the pressing member 5 rotates from the first rotary position (See FIG. 2) to the second rotary position (See FIG. 4), the projection 131 moves relative to and within the recess 132 and comes into contact with the inside surface of the recess 132, resulting in prevention of further travel of the projection 131. The projection 131 is disposed in the body 4, and the recess 132 is disposed in the pressing member 5. Actually, when the recess 132 moves, and the inside surface of the recess 132 comes into contact with the projection 131, the movement of the recess 132, in other words, the rotation of the pressing member 5, is prevented.

The interlock means 140 causes the pressing member 5 in the second rotary position to move between the press releasing position and the pressing position and interlocks with the rotation of the rotary member 6 between the middle rotary position (See FIGS. 4 and 5) and the other rotary position (See FIGS. 6 to 9). Specifically, the interlock means 140 includes: a guide means 150 for axially guiding the rotary member 6 by rotating the rotary member 6, and a support means 160 for supporting the pressing member 5 so that it moves between the press releasing position and the pressing position along with the axial movement of the rotary member 6. Thus, the rotary member 6, as it rotates between the middle rotary position and the other rotary position, is guided to axially translate. Along with this movement, the pressing member 5 supported by the support means 160 moves between the press releasing position on the press releasing side and the pressing position on the pressing side. Here, the guide means 150 includes: a guided projection 151 provided in one of the body 4 and the rotary member 6, and a first guide surface 152 provided in the other of the body 4 and the rotary member 6, for guiding the guided projection 151 relative to the first guide surface 152. In other words, as the guided projection 151 is guided relative to and with the first guide surface 152, the rotary member 6 is guided to axially translate.

The support means 160 includes: the coil spring 8 serving as a resilient element for urging the pressing member 5 toward the press releasing position from the pressing position; and a receiving portion 6 c that is provided on the rotary member 6 to receive the pressing member 5 against the urging force of the coil spring 8 as a resilient element. Thus, as the rotary member 6 rotates between the middle rotary position and the other rotary position and is guided by the guide means 150 to translate, along with the axial movement, the pressing member 5 urged by the coil spring 8, and is received by the receiving portion 6 c of the rotary member 6 and axially translates between the press releasing position and the pressing position. The guided projection 151 is disposed in the rotary member 6, and the first guide surface 152 is disposed in the body 4.

Specifically, the body 4 includes: a plate-like base portion 4 b, and a cylindrical portion 4 c projected upward from the central portion of the base portion 4 b. Here, the base portion 4 b has attachment holes 4 d for attachment bolts 11 to pass through for securing the body 4 to the support base 1. The cylindrical portion 4 c has a base portion in which a step 4 e of a greater diameter is formed. The inside of the cylindrical portion 4 c constitutes the axial bore 4 a and passes through the cylindrical portion 4 c and the base portion 4 b. To the fore-end of the cylindrical portion 4 c is mounted a pin 4 f with its base end side embedded. The projecting tip of the pin 4 f serves as the projection 131 which is the rotary range restricting means 130.

The cylindrical portion 4 c is formed with a first elongate slot 4 g and a second elongate slot 4 h continuously connected with each other (See FIG. 1). The inside peripheral surface of the first elongate slot 4 g serves as the first guide surface 152 for guiding the guided projection 151 of the rotary member 6 relative to the first guide surface 152 when the rotary member 6 rotates between the middle rotary position and the other rotary position.

The inside peripheral surface of the second elongate slot 4 h serves as the second guide surface 171 for guiding the guided projection 151 relative to the second guide surface 171 when the rotary member 6 rotates between the one rotary position and the middle rotary position. The guided projection 151, the second guide surface 171, the holding means 120 and the contact means 110 together guide the pressing member 5, while being in the press releasing position, from the side distant from the pressing position to the side near the pressing position as the pressing member 5 rotates from the first rotary position (See FIGS. 2 and 3) to the second rotary position (See FIGS. 4 and 5). The coil spring 8 is fitted over the cylindrical portion 4 c of the body 4. In addition, an outer cylinder 10 is fitted over the coil spring 8. One end face of the coil spring 8 is in contact with the step 4 e of the body 4 while the other end face is in contact with a raised step 10 a formed on the inside surface of the outer cylinder 10.

The rotary member 6 includes the shank portion 6 a inserted in the axial bore 4 a of the body 4 so as to be rotatable about and slidable along the axis 7, and the receiving portion 6 c located on the fore-end side of the shank portion 6 a. The shank portion 6 a and the receiving portion 6 c are joined as a single member with a bolt 6 d as a securing member. A guide pin 6 e is inserted in the shank portion 6 a and secured with a set screw 6 f. The projecting fore-end of the guide pin 6 e is the guided projection 151 constituting the guide means 150.

The receiving portion 6 c has a disk like shape with its circumferential surface provided with a detachable operation handle 6 g for manual rotation. A surface (the underside) of the receiving portion 6 c facing the pressing member 5 is the second sliding surface 6 b. The receiving portion 6 c is provided with the plunger 9 as embedded therein, with the pressing piece 9 a resiliently urged to project outside and recede inside the second sliding surface 6 b.

The pressing member 5 has the shape of a horizontally elongated plate and the through-hole 5 a is formed at one side thereof to pass through. As the shank portion 6 a of the rotary member 6 is inserted in the through-hole 5 a, the pressing member 5 is allowed to rotate about and slide along the axis 7. A surface (the upside) of the pressing member 5 that faces the receiving portion 6 c of the rotary member 6 is the first sliding surface 5 b. To the other side of the pressing member 5 is attached using a bolt 5 d, a fitting 5 c for pressing the workpiece 2. The recess 132, constituting the rotary range restricting means 130, is formed along the circumference of the through-hole 5 a in the pressing member 5. The recess 132 opens to the through-hole 5 a side and the bottom side.

While respective FIGS. 6 to 7, and FIGS. 8 to 9 show a state in which the rotary member 6 is in the other rotary position and the pressing member 5 is in the second rotary position and pressing position, FIGS. 6 and 7 show a target position, calculated from design, where the workpiece 2 is to be pressed. FIGS. 8 and 9 show the rotary member 6 and the pressing member 5 having advanced furthermore from the target position, with the rotary member 6 in the maximum rotary position and the pressing member 5 in the maximum pressing position.

FIGS. 10 and 11 show an example of clamping the workpiece 2 to a fixture base 1 a, using four sets of the clamp device 3. FIG. 10 is a perspective view, showing a state in which the workpiece 2 is not yet placed or has been removed. FIG. 11 is a perspective view, showing a state in which the workpiece 2 is clamped. In the drawings, reference numeral 1 b denotes supporters which are mounted on the fixture base 1 a to support the workpiece 2. Reference numeral 1 c denotes spacers which are likewise mounted on the fixture base 1 a for the clamp devices 3 to be secured to, respectively. Thus, the support base 1 of the embodiment shown in FIGS. 10 and 11 includes the supporters 1 b, and spacers 1 c, and the fixture base 1 a.

Functional effects of the clamp device 3 constituted as above are described below. With the clamp device 3, when the rotary member 6 is rotated from the one rotary position (See FIGS. 2 and 3) to the middle rotary position (See FIGS. 4 and 5), the pressing member 5, while being held in the press releasing position by the holding means 120, is rotated by the contact means 110 from the first rotary position to the second rotary position, as the rotary member 6 rotates. When the rotary member 6 is rotated further from the middle rotary position (See FIGS. 4 and 5) to the other rotary position (See FIGS. 6 to 9), the pressing member 5, while remaining in the second rotary position by the rotary range restricting means 130, is moved by the interlock means 140 from the press releasing position to the pressing position and presses the workpiece 2.

In other words, in order to clamp the workpiece 2 to the support base 1, first the workpiece 2 is placed in the clamping position and the rotary member 6 is then rotated from one rotary position past the middle rotary position to the other rotary position. This causes the pressing member 5 to rotate from the first rotary position (See FIGS. 2 and 3) not facing the workpiece 2 to the second rotary position (See FIGS. 4 and 5) facing the workpiece 2 as the rotary member 6 rotates up to the middle rotary position. By the rotation of the rotary member 6 up to the other rotary position, the pressing member 5, while remaining in the second rotary position, moves from the press releasing position (See FIG. 5) on the press releasing side to the pressing position (See FIGS. 7 and 9) on the pressing side to press the workpiece 2. Thus, the workpiece 2 is clamped to the support base 1.

In contrast, if the rotary member 6 is rotated from the other rotary position to the one rotary position side, then the pressing member 5 is moved by the interlock means 140 from the pressing position to the press releasing position side, and as the rotary member 6 rotates, the pressing member 5 is rotated by the contact means 110 from the second rotary position to the first rotary position. In other words, if the workpiece 2 is to be removed from the support base 1, the rotary member 6 is rotated from the other rotary position to the one rotary position. This causes the pressing member 5 to move from the pressing position to the press releasing position side, and to rotate from the second rotary position facing the workpiece 2 to the first rotary position not facing the workpiece 2. Here, the workpiece 2 is removed from the support base 1.

With the clamp device 3 as described above, if the workpiece 2 is to be placed on and clamped to the support base 1 or if the workpiece 2 is to be removed from the support base 1, because rotating the rotary member 6 causes the pressing member 5 to rotate between the first rotary position not facing the workpiece 2 and the second rotary position facing the workpiece 2, and to move between the press releasing position on the press releasing side and the pressing position on the pressing side, the workpiece 2 is easily clamped to or removed from the support base 1.

As for the contact means 110, because the first sliding surface 5 b and the second sliding surface 6 b of the pressing member 5 and the rotary member 6 facing each other are urged by the coil spring 8 to tightly contact each other, the pressing member 5 securely rotates between the first rotary position and the second rotary position as the rotary member 6 rotates. In addition, owing to the engagement of the resiliently urged pressing piece 9 a (engagement portion 112) of the rotary member 6 with the engagement recess 111 of the pressing member 5, the pressing member 5 and the rotary member 6 are prevented from rotating relative to each other.

Therefore, the pressing member 5 rotates more certainly between the first rotary position and the second rotary position as the rotary member 6 rotates. In other words, while the rotary member 6 is being rotated from one rotary position to the middle rotary position, the pressing piece 9 a is in engagement with the engagement recess 111, so that the rotary member 6 and the pressing member 5 rotate together. Rotating the rotary member 6 from the middle rotary position to the other rotary position causes slippage between the first sliding surface 5 b and the second sliding surface 6 c, and also disengagement between the engagement recess 111 and the pressing piece 9 a. In contrast, if the rotary member 6 is rotated from the other rotary position to the one rotary position, the pressing piece 9 a engages the engagement recess 111 in the middle of the rotation.

With the press releasing position of the pressing member 5 having a range, that is, a height difference, due to relationship between the second guide surface 171 (the second elongate slot 4 h) and the guided projection 151 (the guide pin 6 e), when the pressing member 5 rotates from the first rotary position to the second rotary position, the pressing member 5 moves from the side distant from the pressing position to the side near the pressing position.

It is therefore possible to rotate the pressing member 5 apart from the workpiece 2 in the axis 7 direction, that is, the up-and-down direction so that the pressing member 5 can pass an obstacle, if any, while the pressing member 5 moves from the first rotary position to the second rotary position. In addition, because the pressing member 5 approaches the pressing position while it rotates from the first rotary position to the second rotary position, it is possible to reduce the stroke between the press releasing position and the pressing position in the second rotary position. Therefore, it is possible to increase the pressing force with which the pressing member 5 presses the workpiece 2. In particular in the embodiment shown in FIG. 1, because the gradient of the first guide surface 152 (the first elongate slot 4 g) is smaller than the second guide surface 171 (the second elongate slot 4 h), it is possible to further increase the force for pressing the workpiece 2.

Incidentally, the invention is not limited to the above embodiment but may be modified in various ways. For example, the support base 1 may be any table such as an MC pallet, machine table, etc., other than the fixture base 1 a. The object to be clamped may be for example a jig, a fixture, die or the like, other than the workpiece 2.

The contact means 110 in the clamp device 3 includes: the coil spring 8 serving as a resilient member, the engagement recess 111, and the plunger 9 serving as the engagement member 113. However, the engagement recess 111 and the plunger 9 may not be used.

The body 4 has the plate-like base portion 4 b for attachment to the support base 1. Alternatively, as shown in FIG. 12, the body 4 may include: a tool engagement portion 181 to be engaged with a tool such as a wrench; a first thread portion 183 to be engaged with a nut 182; and a second thread portion 184 to be screwed in the support base 1, in vertical order.

The rotary member 6 may not have the operation handle 6 g for rotary operation. Alternatively, a tool engagement portion 191 for engaging a tool 190 such as a wrench may be provided, as shown in FIG. 13.

The rotary range restricting means 130 may not include the projection 131 disposed in the body 4 and the recess 132 disposed in the pressing member 5, but, as shown in FIGS. 14 and 15, may include: a recess 132 as a cut out formed at the top end of an outer cylinder 201 that is fixed to the body 4, and a projection 131 extending sideways from the through-hole 5 a side of the pressing member 5. In other words, the rotary range restricting means 130 may include the recess 132 on the body 4 side and the projection 131 on the pressing member 5 side.

The clamp device 3 includes the coil spring 8 disposed to urge between the body 4 and the pressing member 5. Alternatively, the coil spring 8 may be replaced, as shown in FIG. 16, with a resilient piece 301, which is disposed to urge between the rotary member 6 and the pressing member 5 and serves as a resilient member which constitutes at least the contact means 110, such as a coned disk spring and a spring washer. The resilient piece 301 serves as a resilient body as an element constituting the holding means 120, and also serves as a resilient element as an element constituting the support means 160. Incidentally, in FIG. 16, the projection 131 of the rotary range restricting means 130 is disposed in the pressing member 5, and the recess 132 is disposed in the body 4.

As for the guide means 150, the guided projection 151 is disposed in the rotary member 6, and the guide surfaces 152, 171 are in the body 4. Alternatively, they may be disposed contrarily, with the guided projection 151 disposed in the body 4, and with the guide surfaces 152, 171 in the rotary member 6.

In the contact means 110, while the engagement recess 111 is disposed in the pressing member 5 and the plunger 9 serving as the engagement member 113 is disposed in the rotary member 6, they may be disposed contrarily, with the engagement recess 111 disposed in the rotary member 6 and with the plunger 9 in the pressing member 5.

As described above, the clamp device according to the invention may be used to clamp workpieces, jigs, fixtures, or dies to a fixture base, MC pallet, machine table, for example.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not as restrictive. The scope of the invention is, therefore, indicated by the appended claims and their combination in whole or in part rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope. 

1.-10. (canceled)
 11. A clamp device for clamping an object to a support base, comprising: a body detachably secured to the support base; a pressing member for clamping the object; a rotary member; the body, the pressing member, and the rotary member being combined so as to rotate relative to each other about an axis; the pressing member rotating between a first rotary position not axially facing the object and a second rotary position axially facing the object; and the rotary member rotating between one rotary position on the first rotary position side and another rotary position past a middle rotary position on the second rotary position side; the pressing member axially translating between a press releasing position on a press releasing side and a pressing position on a pressing side so as to press the object and release the press in the second rotary position; a contact means for causing the pressing member and the rotary member to contact with each other so that the pressing member rotates between the first rotary position and the second rotary position as the rotary member rotates; a holding means for holding the pressing member in the press releasing position between the first rotary position and the second rotary position; a rotary range restricting means for preventing the pressing member from rotating from the second rotary position to a side opposite the first rotary position; and an interlock means for moving the pressing member positioned in the second rotary position, between the press releasing position and the pressing position, and interlocking with the rotation of the rotary member between the middle rotary position and the other rotary position; the interlock means comprising a guide means for axially guiding the rotary member with the rotation of the rotary member; and a support means for supporting the pressing member so that said pressing member moves between the press releasing position and the pressing position as the rotary member axially translates; the guide means comprising a guided projection provided in one of the body and the rotary member, and a first guide surface provided in the other of the body and the rotary member, for guiding the guided projection relative to the first guide surface; wherein, when the rotary member rotates from the one rotary position to the middle rotary position, the pressing member, while being held in the press releasing position by the holding means, rotates by the contact means from the first rotary position to the second rotary position as the rotary member rotates, and wherein, when the rotary member rotates from the middle rotary position to the other rotary position, the pressing member, while remaining in the second rotary position by the rotary range restricting means, moves from the press releasing position to the pressing position by the interlock means to press the object, and wherein, when the rotary member rotates from the other rotary position to the one rotary position side, the pressing member moves by the interlock means from the pressing position to the press releasing position side, and the pressing member rotates by the contact means from the second rotary position to the first rotary position as the rotary member rotates, wherein the other of the body and the rotary member includes a second guide surface for guiding the guided projection relative to the second guide surface when the rotary member rotates between the one rotary position and the middle rotary position; wherein the first guide surface is smaller in gradient than the second guide surface; and wherein the pressing member, while being in the press releasing position, is guided by the guided projection and the second guide surface, the holding means, and the contact means, so that said pressing member moves from a side distant from the pressing position to a side near the pressing position as the pressing member rotates from the first rotary position to the second rotary position.
 12. The clamp device according to claim 11, wherein the body has an axial bore; the rotary member has a shank portion that is rotatably inserted in the axial bore so that the rotary member axially rotates; and the pressing member has a through-hole for the shank portion to pass and axially rotates relative to the rotary member.
 13. The clamp device according to claim 11, wherein the rotary range restricting means comprises a projection disposed in one of the body and the pressing member; and a recess formed in the other of the body and the pressing member, and receiving the projection for movement therein, and when the pressing member rotates from the first rotary position to the second rotary position, the projection moves relative to and within the recess and comes into contact with the inside surface thereof, resulting in prevention of further movement of the projection.
 14. The clamp device according to claim 11, wherein the holding means comprises a resilient body for urging the pressing member toward the press releasing position from the pressing position.
 15. The clamp device according to claim 11, wherein the support means comprises a resilient element for urging the pressing member toward the press releasing position from the pressing position and a receiving portion disposed in the rotary member for receiving the pressing member against the urging force of the resilient element.
 16. The clamp device according to claim 11, wherein the contact means comprises a resilient member for urging so that the first sliding surface and the second sliding surface of the pressing member and the rotary member facing each other come into tight contact.
 17. The clamp device according to claim 16, wherein the contact means comprises: the resilient member, an engagement recess provided in one of the pressing member and the rotary member, and an engagement member that is provided in the other of the pressing member and the rotary member, said engagement member including an engagement portion resiliently urged to releasably engage the engagement recess.
 18. A clamp device for clamping an object to a support base, comprising: a body detachably secured to the support base; a pressing member for clamping the object; a rotary member; the body, the pressing member, and the rotary member being combined so as to rotate relative to each other about an axis; the pressing member rotating between a first rotary position not axially facing the object and a second rotary position axially facing the object, and the rotary member rotating between one rotary position on the first rotary position side and another rotary position past a middle rotary position on the second rotary position side; the pressing member axially translating between a press releasing position on a press releasing side and a pressing position on a pressing side so as to press the object and release the press in the second rotary position; a contact means for causing the pressing member and the rotary member to contact with each other so that the pressing member rotates between the first rotary position and the second rotary position as the rotary member rotates; a holding means for holding the pressing member in the press releasing position between the first rotary position and the second rotary position; a rotary range restricting means for preventing the pressing member from rotating from the second rotary position to a side opposite the first rotary position; and an interlock means for moving the pressing member positioned in the second rotary position, between the press releasing position and the pressing position, and interlocking with the rotation of the rotary member between the middle rotary position and the other rotary position; the interlock means comprising a guide means for axially guiding the rotary member with the rotation of the rotary member; and a support means for supporting the pressing member so that said pressing member moves between the press releasing position and the pressing position as the rotary member axially translates; the guide means comprising a guided projection provided in one of the body and the rotary member, and a first guide surface being the inside peripheral surface of the first elongate slot and provided in the other of the body and the rotary member, for guiding the guided projection relative to the first guide surface; wherein, when the rotary member rotates from the one rotary position to the middle rotary position, the pressing member, while being held in the press releasing position by the holding means, rotates by the contact means from the first rotary position to the second rotary position as the rotary member rotates, and when the rotary member rotates from the middle rotary position to the other rotary position, the pressing member, while remaining in the second rotary position by the rotary range restricting means, moves from the press releasing position to the pressing position by the interlock means to press the object, and wherein, when the rotary member rotates from the other rotary position to the one rotary position side, the pressing member moves by the interlock means from the pressing position to the press releasing position side, and the pressing member rotates by the contact means from the second rotary position to the first rotary position as the rotary member rotates, and wherein the other of the body and the rotary member includes a second guide surface being the inside peripheral surface of a second elongate slot continuous from the first elongate slot, and said second guide surface guiding the guided projection relative to the second guide surface when the rotary member rotates between the one rotary position and the middle rotary position; and wherein the pressing member, while being in the press releasing position, is guided by the guided projection and the second guide surface, the holding means, and the contact means, for moving from a side distant from the pressing position to a side near the pressing position as the pressing member rotates from the first rotary position to the second rotary position. 